Design and implementation of a socket with zero standby power using a photovoltaic array

Abstract

This paper further enhances our previous research into reducing the standby power of electric home appliances. Turned-off electric home appliances generally still require standby power when they are plugged in. We present a way to reduce the standby power of a socket. Our socket supplies the appliances with power when the user turns them on. When the user turns them off, our socket shuts the electric power off and thus reduces the standby power. Our design, which uses an MCU, receives signals from a PIR sensor which detects the user approaching the socket. The MCU controls the SSR On/Off when used as an appliance switch for shutting off the standby power. A load current sensor circuit provides a signal to the MCU to keep the SSR on until the appliance has finished its work. The MCU monitoring program provides both automatic detection of the user by the PIR sensor and detection of the load current. The MCU with low-power technology has internal modules to simplify the hardware circuit design. The PV array is added in our design to reduce the consumption from the local electric power company. The standby power consumption of an appliance with our new design is 7 mW in a darkroom and less than 7 mW in a non-darkroom. When the illumination intensity suffices, the consumption is 0 W from the local electric power company.